The Lake Mitchell restoration project is not going to begin this year after all. Barr Engineering, the company primarily overseeing the drawdown and dredging of the lake, said it won’t be able to start until next fall at the earliest.
While the project was set to get started later this year, the City of Mitchell quickly found out that wouldn’t be possible because the South Dakota Department of Agriculture and Natural Resources paused Lake Mitchell’s drawdown.
The state said the city needed to conduct more studies on Lake Mitchell spillway and waterflow rates to approve the drawdown permit.
Eric Lund is with Barr Engineering. At the latest Mitchell City Council meeting he said they didn’t perform the studies because they didn’t know they had to.
“As we moved through the process, right, that a complex project moves through where you’re going through investigations, and doing some preliminary designs, then you’re getting a final design, then you’re getting through permits, we reengaged with the state and had the meeting with numerous different parts of the Department of Agriculture and Natural Resources and then had a follow-up meeting with the dam and safety folks," Lund said. "That was on the 25th of August. Then they decided to—they said they needed some more time to discuss internally what was going to be required. I can’t recall if it was later that week or the following week, but they then came back and said these are what we’re going to require of the city.”
Lund said the spillway and waterflow rate studies are “desktop, paper” studies analyzing precipitation trends, but he expects them to take three to six months. He explained specifically what the state is wanting to see in a hydrologic model when large amounts of water enter the dam.
“How much water could be coming into the lake. Right? From the precipitation and the flow rate perspective, and then is the damn high enough, is the spillway large enough to store and pass those flows in a safe manner without overflowing," Lund said. "You want to overtop that. When I talk about the free board, for example, builds up too much, you get strong winds and waves that can go over the top, start to erode, things like that.”
However, these studies don’t come free and mean an estimated $100,000-200,000 more to the cost of the project. Councilors said that would probably come out of the $3.2 million in the Mitchell Lake contingency fund.
City Councilors and Mayor Jordan Hanson requested Barr Engineering to create a checklist for the project and its studies to avoid other unexpected delays like this one.
